Pagedaemon and shared memory [was: Heavy system load by pagedaemon].

[Yaron Zabary]

  I am observing similar symptoms as described in the original letter (by
Iasen Kostov). I am using the vmware3 port. My desktop machine is a P3 1Gh
with 512Mb. The vmware guest (a Windows 2000) is allocated 256Mb. Every
once in a while (around five times a day), the machine freezes. The clock
on the toolbar stops counting the seconds. I have top running on a session
from another machine (it is a second machine I can switch to using KVM)
which also freezes (no screen refresh). Disk activity is heavy (lamp is
on). After over 30 seconds, the machine is back to normal and everything
works fine. The vmware process resident size goes down from ~200Mb to
~100Mb. I also notices some relations to running acroread 7 with large PDF
files (which might also need shared memory for its operation). I had the
exact same problem on the same box when I was running FreeBSD 4.10 (which
I attributed at first to a bad disk, which was replaced when I upgraded
from 4.10 to 6.1).

  Details of my setup:

zed# pkg_info | grep acro
acroread7-7.0.1,1   Adobe Reader for view, print, and search PDF documents
(ENU
acroreadwrapper-0.0.20060221 Wrapper script for Adobe Reader
zed# pkg_info | grep vmware
vmware3-3.2.1.2242_13,1 A virtual machine emulator - a full PC in a window
zed# uname -a
FreeBSD zed.tau.ac.il 6.1-RELEASE FreeBSD 6.1-RELEASE #0: Sun May  7
04:32:43 UTC 2006
root at opus.cse.buffalo.edu:/usr/obj/usr/src/sys/GENERIC  i386
zed# vmstat -s
3085682937 cpu context switches
1891952501 device interrupts
102932808 software interrupts
224976183 traps
3444466737 system calls
       43 kernel threads created
    90785  fork() calls
     9290 vfork() calls
        0 rfork() calls
   152515 swap pager pageins
   320318 swap pager pages paged in
   109683 swap pager pageouts
   335657 swap pager pages paged out
   607136 vnode pager pageins
  1527655 vnode pager pages paged in
   382684 vnode pager pageouts
   674383 vnode pager pages paged out
    13048 page daemon wakeups
169035203 pages examined by the page daemon
  1758718 pages reactivated
  4566067 copy-on-write faults
     3783 copy-on-write optimized faults
119970368 zero fill pages zeroed
101409420 zero fill pages prezeroed
   160241 intransit blocking page faults
144326574 total VM faults taken
        0 pages affected by kernel thread creation
  6901381 pages affected by  fork()
  1204954 pages affected by vfork()
        0 pages affected by rfork()
185857018 pages freed
      187 pages freed by daemon
 51557423 pages freed by exiting processes
    44604 pages active
     7181 pages inactive
     3777 pages in VM cache
    64942 pages wired down
     5806 pages free
     4096 bytes per page
1945885066 total name lookups
          cache hits (95% pos + 4% neg) system 0% per-directory
          deletions 0%, falsehits 0%, toolong 0%


-- Yaron.